Cap assembly



United States Patent 2,810,401 10/1957 Stansbury 220/24.5(UX) 3,175,7273/1965 Piel .4 220/245 FOREIGN PATENTS 148 .398 2/1904 Germany 220/24519,835 6/1901 Great Britain 215/54 Primary ExaminerLaverne D. GeigerAssistant Examiner-Edward J. Earls Attorney-A. Yates Dowell and A. YatesDowell, Jr.

ABSTRACT: An assembly for mounting a cap on the end of a tubular memberincludes an anchor member having a central bowed section extendinggenerally transversely of the tube, foot members extending generallyparallel to the tube axis from each end of the bowed section toward thecap, a bolt connecting the cap and the anchor member for biasing theends of the bowed section outwardly into engagement with the wall of thetube, flanges on the bowed section for holding a nut threaded on thebolt against rotation, and a flat washer positioned between the anchorand the cap CAP ASSEMBLY BACKGROUND or THE INVENTION 1. Field of theInvention This invention relates generally to connector elements fortubular structures and more particularly to a device for attachingmembers to the ends of tubular structures. While the invention isparticularly intended for the attachment of an ornamental and protectivecap to the ends of tubes used in hand rails and fences, it may lenditself to other uses for tubular structures such as in formingscaffolding and table legs with tubes.

2. Description of the Prior Art Hand rails, fences, etc. are frequentlymade of tubular rail and post sections which are cut to size and joinedat the site of the installation. The exposed ends of such posts andrails are cutting of threads. This may require excessive material andmay make difficult the use of simple manufacturing processes such asstamping for forming the caps or extrusion for forming the pipes. Thisalso makes it more difficult to cut the tubes to size to fit aparticular installation since the threads on the tube would have to becut at the installation site.

Connectors have been provided which can be used on the ends of a plaintube, but these have been expensive to manufacture since the parts mustbe machined to close tolerances so that cap and tube will be alignedwhen connected. In addition, the tube itself must be made to closetolerances, since alignment of cap and tube may be difficult if thetubes inner surface is not precisely positioned relative to its outersurface.

Alignment of cap and tube is also difficult when polygonal or othernoncircular tubes or caps are used. It is desirable to provide aconnector which facilitates alignment of either circular or noncirculartubes and caps.

It has often been difficult to construct prior art connecting structuresfrom a material matching that-of the tubes and caps. Use of the samematerial minimizes corrosion problems and has an intangible advantage inemphasizing to the purchaser that the tubes and connectors are part of acommon set. In

recent years, some tubes .and caps have been made of such materials asaluminum and plastics. It is desirable to provide a connector elementwhich may be fabricated from such materials by such processes asstamping, extrusion, and injection molding, or which may be fabricatedby earlier known processes or with earlier known materials.

Prior art connectors for joining tubular structuresoften requiredconsiderable manual dexterity to assemble parts concealed within thetubes and were often complex in structure.

Assembly often involved the risk that a part might be lost by droppingit into an inaccessible section of the tube.

SUMMARY OF THE INVENTION Briefly stated the present invention includesan anchor member which is used to connect an end'member such as anornamental cap to a tube. The anchor member includes a bowed centralsection extending transversely across a tube, an opening for a threadedbolt connected to the end member, flanges for engaging the sides of anut connected to the bolt and legs connected to the ends of the curvedsection and engaging the end member. 'l:ightening of the bolt flattensthe Among the objects of the present invention is the provision of aconnector element for joining a cap to a tube and which permits easyalignment of the cap relative to the tube prior to tightening.

A further object of the invention is to provide such a connectorassembly which is simple and inexpensive to manufacture and requires noclose tolerances either in its own manufacture, or in the manufacture ofthe caps and the tubes with which it is used, and which may be easilyconnected to a tube by unskilled or. inexperienced persons. 7

A further object is the provision of such a connector element which maybe made from aluminum by an extrusion process.

A still further object is the provision of such a connector elementwhich in use will be largely concealed within the tube to improve theornamental appearance and minimize the danger caused by projectingparts.

A still further object is the provision of such a connector elementwhich may be used for joining various types of 'end members other thanornamental caps to tubular members.

Other object and advantages of .the invention will beapparent from thefollowing description considered in conjunction with the accompanyingdrawing.

BRIEF DESCRIPTION OFITHE DRAWING FIG. 1 is a sectional view on the line1-1 of FIG. 2; FIG. 2, a sectional view on the line 2-2 of FIG. 1;

FIG. 3, a cross-sectional view similar to FIG. 1 of a cap according to adifferent embodiment of the invention; and

FIG. 4, a perspective of the anchor member.

DESCRIPTION or ONE EMBODIMENT With reference to the drawing, a capassembly 10 is provided for attachment to the end of a tube 11.According to the present invention, the cap assembly 10 includes a cap12 to which a flatwasher 14 andan anchor member 16 are adjustablyconnected. The anchor member 16 is of generally channel shape andincludes a bowed section 18 having substantially parallel foot members22 at opposite sides thereof. A threaded bolt 24 passes throughgenerally centrally aligned openings 26, 28 and 30 in cap 12, washer l4and anchor member 16, respectively, and is threaded within a nut 32received within a channel 31 on the convex face of curved section 18.

Cap 12 is formed in any desired manner, as by stamping and includes acentral spherically curved dish portion 33 tenninating in a generallycylindrical rim 34 of the same outer diameter as tube 11. Centralopening 26 in the cap preferably is countersunk for the head 36 of bolt24.

Washer 14 fits within the cap 12 and provides a flat surface againstwhich the foot members 22 of anchor member 16 can bear. Its centralopening 28 is slightly larger than the outside diameter of bolt 24.

Anchor member 16 is fonned from any desired material such as aluminum.It includes a central section 40 formed of a relatively thick base 41having a pair of spaced flanges 42 projecting therefrom defining channel31 which is slightly wider than nut 32. Wing sections 43 project at anangle from each side of base 41 and form with it bowed section 18 ofanchor member 16. Wing sections 43 are approximately one-half thethickness of base 41. Foot members 22 extend from the ends of wingsections 43 in a direction opposite flanges 42. The foot members aretapered and are thicker adjacent the wing section than at their outerends 44. Ends 44 are rounded. Foot members 22, even'at their outer ends,are substantially thicker than wing sections 43 so they will not bucklewhen bolt 24 is tightened. Instead bending takes place in the relativelythin wing sections. The outer surface of each foot member 22 has a pairof serrated grooves 46, 47'formed therein adjacent their juncture withthe outer end of wing sect'on 43.

As illustrated in FIG. 2, the distance between foot members 22, as wellas the length of such members, is determined by the inner periphery ofthe tube 11. In other words, a tube having a slightly larger innerperiphery could use an anchor member 16 similar to that shown in FIG. 2except that the foot member 22 would be of greater length so that theouter edges of such foot members would engage the inner periphery of thetube when the bowed portion 18 is expanded. Conversely, a tube having aslightly smaller inner periphery could use an anchor member similar tothat illustrated with the exception that the length of the foot memberswould be shorter. Tubes having substantially diflerent inner peripherieswould require a greater or lesser spacing between the foot members 22.

OPERATION In use anchor member 16 is loosely secured within the concaveportion of cap 12 with washer l4 interposed therebetween. Nut 32 isthreaded onto the bolt and the bolt is tightened enough to draw the nutloosely into channel 20 but not tightly enough to bend wing sections 43.The nut is maintained sufficiently loose so that the legs 22 may slideon the flat surface of the washer.

- The cap and anchor member as thus assembled are applied to the tube11. The position of cap 12 is adjusted so that rim 34 is in engagementwith the end 54 of the tube 11 and with the outer surface 55 of cap rim34 aligned with the outer surface 56 of tube 11. The loose positioningof nut 32 permits the foot members 22 of the anchor member to slide uponwasher 14. Bolt 24 is then tightened by turning its head 36 with ascrewdriver or the like. Rotation of the bolt 24 draws the base 41toward the cap 12 and moves foot members 22 outwardly by bending wingsections 43. Portions of the outer comers 52 of the foot members willengage the inner surface of the tube 11 and may be slightly flattened,as illustrated in FIG. 2, but holding action is adequate.

DESCRIPTION OF A MODIFICATION FIG. 3 illustrates a different embodimentof the invention. This is substantially similar to the embodiment ofFIGS. 1 and 2 except that cap 12' is formed with a flat inner surface15' thus eliminating the need for the washer 14 of the other embodiment.When nut 32 is loose, the foot members 22 are free to slide on surface15 to permit precision alignment of cap 12 on the tube 11.

It will be obvious to one skilled in the art that various changes may bemade in the described embodiment of the invention without departing fromthe spirit and scope thereof and therefore the invention is not limitedby that which is illustrated in the drawing and described in thespecification, but only as indicated in the accompanying claims.

lclaim:

1. Apparatus for mounting a closure cap on the end of a tubular memberand in generally coextensive alignment therewith comprising an anchormember having a relatively thick base portion, a pair of relatively thinbowed wing portions extending outwardly from opposite sides of said baseportion, an enlarged foot member fixed to the outer end of each wingportion, a generally flat surface located between said cap and saidanchor member and adapted to be slidably engaged by the ends of saidfoot members remote from said wing portions, said anchor member being ofa length and width so that portions of said foot members are locatedwithin said tubular member and in proximity to the inner peripherythereof, flange means connected to said base portion and extendingoutwardly therefrom in a direction opposite said foot members,adjustable fastening means extending through said cap and said anchormember and threadedly engaging nut means exteriorly of said baseportion, said flange means adapted to prevent rotation of said nut meanswhen said fastening means is rotated, whereby rotation of said fasteningmeans will draw the base portion of said anchor member toward said capand cause said foot members to s read outwardly rnto engagement with theinner periphery 0 said tubular member.

2. The structure of claim 1 in which said flat surface is a washerlocated between said cap and said anchor member.

3. The structure of claim 1 in which said flat surface is part of saidcap.

4. The structure of claim 1 in which said foot members include serratedgrooves along the outer sides thereof.

